Vibration reduction and isolation device and method based on magnetorheological damper and piezoelectric stack
By combining magnetorheological dampers and piezoelectric stacks to form a vibration reduction and isolation device, adaptive control of vibrations in different frequency bands is achieved, solving the problem of insufficient mid-frequency band adaptability in existing technologies and providing a vibration isolation solution with fast response and high safety.
Patent Information
- Application Number
- CN202511218105.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-28
- Publication Date
- 2026-01-20
AI Technical Summary
Existing technologies struggle to achieve vibration isolation effects across different frequency bands in vibration control, particularly lacking adaptability and reliability under low-frequency, mid-frequency, and high-frequency vibrations, which limits equipment accuracy and safety.
A vibration reduction and isolation device based on magnetorheological dampers and piezoelectric stacks is adopted. By combining the voltage control of the piezoelectric stacks and the current regulation of the magnetorheological dampers, adaptive cancellation of vibrations in different frequency bands can be achieved, including suppression of low-frequency large-amplitude vibrations and control of mid-to-high-frequency micro-vibrations.
It achieves excellent vibration reduction in scenarios involving superposition of low-frequency large displacement disturbances and high-frequency micro-vibrations, and features rapid response, high adaptability, and high safety, meeting the broadband adaptive vibration isolation requirements of precision manufacturing, aerospace, and automotive equipment.
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Figure CN121363611A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of structural vibration reduction, and more particularly to a vibration reduction and isolation device and method based on a magneto-rheological damper and a piezoelectric stack. BACKGROUND
[0002] Vibration is widespread in the engineering fields of mechanical equipment, transportation, precision instruments, and aerospace. Excessive vibration not only reduces the working precision and reliability of equipment, but also accelerates structural fatigue damage, and even causes safety accidents. With the development of high-end equipment manufacturing, aerospace (such as aircraft structure vibration control), precision instruments (lithography machines, electron microscopes), and vehicle engineering, full-band vibration control has become a core requirement. For example, aircraft structures have the characteristics of "flexibility, low natural frequency, and modal density", and precision machining needs to suppress full-frequency interference from ground vibration to high-frequency excitation of equipment. In order to improve the precision of precision machining and the sensitivity of measurement, the wideband micro-vibration of the precision platform must be suppressed. Vibration isolation technology is currently the main method to suppress platform vibration, that is, a vibration isolation system is installed between the instrument and its elastic foundation to cut off the propagation path of vibration. Common vibration isolation technologies include passive, semi-active, and active vibration isolation.
[0003] Passive vibration isolation has simple structure and good stability, but the vibration isolation performance is limited by the natural frequency, and the effect on low-frequency vibration is poor, and the adaptability is insufficient under frequency change or impact environment. Active vibration isolation relies on a driving device to generate a control force to counteract vibration, which can effectively deal with low-frequency and complex disturbances, but the system structure is complex, the power consumption is high, and it is highly dependent on sensors and control systems, and has a high risk of failure in the event of power failure. Semi-active vibration isolation combines the advantages of passive and active, and improves the vibration isolation performance by adjusting the damping or stiffness in real time, has lower energy consumption and higher safety, but the adjustment range and response speed are limited by the characteristics of materials and actuators.
[0004] Therefore, there is currently a lack of a vibration reduction and isolation scheme that can take into account different frequency bands and has better adaptability and reliability.
[0005] In view of the above problems, the present application is proposed. SUMMARY
[0006] The present application is proposed in view of the above problems. According to one aspect of the present application, a vibration reduction and isolation device based on a magneto-rheological damper and a piezoelectric stack is provided, comprising: an outer sleeve, a magneto-rheological damper, a piezoelectric driver, an intermediate mass, a lower cover plate, a first vibration sensor, and a control module; the lower cover plate is arranged at the bottom of the outer sleeve; the lower cover plate is used to connect a vibration source; the first vibration sensor is used to collect a first vibration signal of a vibration-isolated structure; the magneto-rheological damper, the piezoelectric driver, and the intermediate mass are all located in a space composed of the outer sleeve and the lower cover plate; The piezoelectric driver comprises a piezoelectric shell, an output rod and a piezoelectric stack; the piezoelectric stack is arranged in the inner cavity of the piezoelectric shell, the bottom of the output rod is connected with the piezoelectric stack, and the top of the output rod penetrates through the piezoelectric shell and is used for connecting the vibration-isolated structure; the bottom of the piezoelectric shell is connected with the intermediate mass block, the intermediate mass block can slide up and down in the outer sleeve; the upper end of the magneto-rheological damper is hinged to the outer sleeve, and the lower end of the magneto-rheological damper is hinged to the top of the intermediate mass block. The control module is connected with the first vibration sensor, the piezoelectric stack and the magneto-rheological damper; the control module is used for acquiring the first vibration signal collected by the first vibration sensor, and controlling the voltage of the piezoelectric stack and the current of the magneto-rheological damper based on at least the first vibration signal, so as to offset the vibration energy.
[0007] Exemplarily, a spring is further included; the top of the spring is connected with the bottom of the intermediate mass block, and the bottom of the spring is connected with the lower cover plate. Preferably, the spring is a variable stiffness spring.
[0008] Exemplarily, the spring is provided with a retainer on both sides.
[0009] Exemplarily, the number of the magneto-rheological dampers is multiple, the multiple magneto-rheological dampers are uniformly arranged relative to the piezoelectric driver; the number of the springs corresponds to the number of the magneto-rheological dampers, and the springs are arranged on the opposite side of the magneto-rheological dampers relative to the mass block.
[0010] Exemplarily, the bottom of the output rod is provided with an adapter, the output rod is connected with the piezoelectric stack via the adapter; a disc spring is arranged between the adapter and the top wall of the inner cavity of the piezoelectric shell, and the disc spring is sleeved on the output rod. Preferably, the side of the adapter close to the piezoelectric stack is spherical.
[0011] Exemplarily, a circular hole is formed in the outer sleeve, the diameter of the circular hole is greater than the diameter of the piezoelectric shell; the top of the piezoelectric shell penetrates through the outer sleeve via the circular hole.
[0012] The embodiment further provides a vibration isolation method, which adopts the device described above; the method comprises the following steps: acquiring the first vibration signal collected by the first vibration sensor; controlling the voltage of the piezoelectric stack and the current of the magneto-rheological damper based on at least the first vibration signal, so as to offset the vibration energy.
[0013] Exemplarily, the step of controlling the voltage of the piezoelectric stack and the current of the magneto-rheological damper based on at least the first vibration signal comprises: determine a dominant frequency of the external excitation based on the first vibration signal; adjust a voltage of the piezoelectric stack based on at least the first vibration signal when the dominant frequency is in a low frequency band; adjust a current of the magneto-rheological damper based on at least the first vibration signal when the dominant frequency is in a medium frequency band; turn off the piezoelectric stack and the magneto-rheological damper when the dominant frequency is in a high frequency band.
[0014] Exemplarily, the adjusting the voltage of the piezoelectric stack based on at least the first vibration signal comprises: calculating the voltage of the piezoelectric stack based on at least the first vibration signal and using an active control algorithm; and / or, the adjusting the current of the magneto-rheological damper based on at least the first vibration signal comprises: calculating the current of the magneto-rheological damper based on at least the first vibration signal and using a semi-active control algorithm.
[0015] Exemplarily, the determining the dominant frequency of the external excitation based on the first vibration signal comprises: performing fast Fourier transform processing on the first vibration signal to obtain a frequency distribution of the first vibration signal; determining the dominant frequency according to the frequency distribution.
[0016] The device of the above technical solution can take into account low-frequency large-amplitude vibration suppression and medium-high-frequency micro-vibration control by combining the application of the piezoelectric stack and the magneto-rheological damper, can achieve good vibration reduction and isolation effect in a scene where low-frequency large-displacement disturbance and high-frequency micro-vibration are superimposed, and has the characteristics of fast response speed, high adaptability, and high safety, and can meet the strict requirements of precision manufacturing, aerospace, vehicle-mounted equipment, and the like for wideband and self-adaptive vibration isolation.
[0017] The above description is only a summary of the technical solution of the present application, in order to more clearly understand the technical means of the present application, the content of the specification can be implemented, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS
[0018] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the figures. The drawings provided are for illustrative purposes only and, therefore, should not be considered to limit the present application. In the drawings:
[0019] Figure 1 A structural schematic diagram of a vibration isolation device based on a magneto-rheological damper and a piezoelectric stack of the embodiment is shown. Figure 2 A structural schematic diagram of a piezoelectric driver of the embodiment is shown. Figure 3 A schematic flow chart of a vibration isolation method of the embodiment is shown.
[0020] In the figure: 1, piezoelectric driver; 101, output rod; 102, disc spring; 103, piezoelectric shell; 104, piezoelectric stack; 2, outer sleeve; 3, magneto-rheological damper; 4, intermediate mass; 5, retainer; 6, spring; 7, lower cover plate. DETAILED DESCRIPTION
[0021] In order to make the objectives, technical solutions and advantages of the present application more apparent, the following will describe the example embodiments according to the present application in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the example embodiments described herein. Based on the embodiments of the present application described in the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present application.
[0022] In order to make the objectives, technical solutions and advantages of the present application more apparent, the following will describe the example embodiments according to the present application in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the example embodiments described herein. Based on the embodiments of the present application described in the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present application. Figures 1-3 One specific embodiment of the present application is described.
[0023] Figure 1 A structural schematic diagram of a vibration isolation device based on a magneto-rheological damper and a piezoelectric stack of the embodiment is shown. Figure 2 A structural schematic diagram of a piezoelectric driver of the embodiment is shown. As Figures 1-2 The embodiment provides a vibration isolation device based on a magneto-rheological damper 3 and a piezoelectric stack 104, comprising: an outer sleeve 2, a magneto-rheological damper 3, a piezoelectric driver 1, an intermediate mass 4, a lower cover plate 7, a first vibration sensor and a control module; the lower cover plate 7 is arranged at the bottom of the outer sleeve 2; the lower cover plate 7 is used for connecting a vibration source; the first vibration sensor is used for collecting a first vibration signal of a vibration-isolated structure; the magneto-rheological damper 3, the piezoelectric driver 1 and the intermediate mass 4 are all located in a space composed of the outer sleeve 2 and the lower cover plate 7.
[0024] The piezoelectric driver 1 comprises a piezoelectric shell 103, an output rod 101 and a piezoelectric stack 104; the piezoelectric stack 104 is placed in the inner cavity of the piezoelectric shell 103, the output rod 101 is connected with the piezoelectric stack 104 at the bottom and penetrates through the piezoelectric shell 103 at the top for connecting the isolated structure; the bottom of the piezoelectric shell 103 is connected with the intermediate mass 4 which can slide up and down in the outer sleeve 2; the magneto-rheological damper 3 is hinged at the top to the outer sleeve 2 and at the bottom to the top of the intermediate mass 4.
[0025] The control module is connected with the first vibration sensor, the piezoelectric stack 104 and the magneto-rheological damper 3; the control module is used to acquire the first vibration signal collected by the first vibration sensor and control the voltage of the piezoelectric stack 104 and the current of the magneto-rheological damper 3 based on at least the first vibration signal to offset the vibration energy.
[0026] The top of the output rod 101 can be threaded to facilitate the connection of the isolated structure. Of course, the output rod 101 can also be connected by means such as clamping, plugging, welding, etc., which will not be described in detail.
[0027] The bottom of the piezoelectric shell 103 in this embodiment can be connected with the intermediate mass 4 by bolts, similarly, the outer sleeve 2 can also be connected with the lower cover plate 7 by bolts, which will not be described in detail.
[0028] The vibration sensor in the present application can be any one or several sensors that can collect vibration signals of the structure (e.g. the vibration source and the isolated structure) in the prior art or to be developed in the future, which can be represented by data collected by the corresponding sensor, and which includes horizontal vibration signals and vertical vibration signals. The vibration sensor includes but is not limited to displacement sensors, velocity sensors, acceleration sensors, optical sensors, etc. For example, the vibration sensor can be a displacement sensor, which can measure the displacement change in the vibration of the structure, i.e. the change of position relative to the reference position, in which embodiment the vibration signal can be represented by the displacement data collected by the displacement sensor. For another example, the vibration sensor can be a velocity sensor, which can measure the velocity change of the structure in the vibration, reflecting the energy size of the vibration of the structure, in which embodiment the vibration signal can be represented by the velocity data collected by the velocity sensor. For another example, the vibration sensor can be an acceleration sensor, which measures the acceleration size of the structure in the vibration, reflecting the impact force size of the structure, in which embodiment the vibration signal can be represented by the acceleration data collected by the acceleration sensor. For another example, the vibration sensor can be an optical sensor, which can obtain vibration displacement, velocity and acceleration information through optical principles, and can directly measure the micro-vibration of the surface of the structure, in which embodiment the vibration signal can include the vibration displacement, velocity and acceleration information collected by the optical sensor. Those skilled in the art can understand the specific way of collecting vibration signals by various sensors, which is not described here.
[0029] In the present embodiment, the vibration transmission path is: vibration source - lower cover plate 7 - outer sleeve 2 - magnetorheological damper 3 - intermediate mass 4 - piezoelectric driver 1 - isolated object. As can be seen from the transmission path, when the device is working, the vibration of the vibration source is first passively isolated by the magnetorheological damper 3, and then actively isolated by the piezoelectric driver 1 to offset the residual vibration. At the same time, when the power supply fails, the device can still play a certain vibration reduction and isolation effect.
[0030] The device of the present embodiment has faster response capability and higher adaptability. Specifically, the piezoelectric driver 1 can achieve millisecond-level active control and can compensate for high-frequency micro-vibration in real time; the magnetorheological damper 3 has short damping adjustment time and can realize real-time matching of system parameters. At the same time, through the adjustable damping characteristics of the magnetorheological damper 3, the equivalent damping of the passive part can be optimized in real time according to the vibration frequency and amplitude, maintaining high isolation performance under different working conditions and avoiding performance decay caused by fixed parameters.
[0031] The device of the above scheme can consider low-frequency large-amplitude vibration suppression and medium-high-frequency micro-vibration control by combining the piezoelectric stack 104 and the magnetorheological damper 3, can achieve good vibration reduction and isolation effect in a scene of low-frequency large-displacement disturbance and high-frequency micro-vibration superposition, and has the characteristics of fast response speed, high adaptability, and high safety, and can meet the strict requirements of precision manufacturing, aerospace, vehicle-mounted equipment, and the like on wide-frequency and self-adaptive vibration isolation.
[0032] With reference to Figure 1 , the device further comprises a spring 6; the top of the spring 6 is connected to the bottom of the intermediate mass block 4, and the bottom is connected to the lower cover plate 7. By arranging the spring 6, on the one hand, the vibration reduction adaptation range can be improved by using the characteristics of the spring 6, and the passive vibration isolation capability can be improved; on the other hand, the spring 6 can provide rigid support for the intermediate mass block 4 to prevent the tensile force caused by the weight of the intermediate mass block 4 from damaging the magnetorheological damper 3.
[0033] In some implementation schemes, the spring 6 is a variable stiffness spring 6. By arranging the variable stiffness spring 6, the stiffness of the spring 6 can be adaptively changed according to the vibration condition, which helps to change the natural frequency of the system, avoid the resonance point in real time, and widen the low-frequency adaptation range. In cooperation with the control force actively output by the piezoelectric driver 1, low-frequency vibration can be further suppressed. At the same time, the variable stiffness characteristic of the variable stiffness spring 6 can automatically optimize the equivalent stiffness of the spring 6 according to the actual vibration scene, maintain high vibration isolation performance under different working conditions, and avoid performance degradation caused by fixed parameters.
[0034] With reference to Figure 1 , the spring 6 is provided with a retainer 5 on both sides. The retainer 5 can limit the horizontal degree of freedom of the spring 6, thereby helping to ensure that the intermediate mass block connected with the spring 6 only moves in the vertical direction and avoids left-right shaking.
[0035] The number of the magnetorheological dampers 3 in the embodiment is multiple, and the multiple magnetorheological dampers 3 are uniformly arranged relative to the piezoelectric driver 1; the number of the springs 6 corresponds to the number of the magnetorheological dampers 3, and the springs 6 are arranged on the opposite sides of the magnetorheological dampers 3 relative to the mass blocks.
[0036] In the structure as shown in Figure 1 , the number of the magnetorheological dampers 3 is two, and the two magnetorheological dampers 3 are symmetrically arranged on the left and right sides of the piezoelectric driver 1.
[0037] The above scheme uses multiple magnetorheological dampers 3 evenly arranged along the circumference (with the piezoelectric actuator 1 as the center) and corresponding variable stiffness springs 6 on the opposite side to achieve coordinated suppression and mechanical balance of multi-directional vibration: the magnetorheological dampers 3 provide controllable damping force in real time to dissipate vibration energy, while the springs 6 on the opposite side support the intermediate mass block 4 and counteract the off-center load torque through dynamic stiffness adjustment. The two complement each other to form a closed-loop control of "dynamic and static combination". This symmetrical layout not only improves the stability and anti-interference ability of the system under complex working conditions, but also optimizes the energy distribution efficiency, avoids single-point overload, and provides a uniform feedback environment for the piezoelectric actuator 1, which significantly enhances the dynamic response accuracy and reliability of the overall vibration reduction system.
[0038] See also Figure 1 , 2 An adapter is provided at the bottom of the output rod 101, through which the output rod 101 connects to the piezoelectric stack 104. A disc spring 102 is provided between the adapter and the top wall of the inner cavity of the piezoelectric housing 103, and the disc spring 102 is sleeved on the output rod 101. The disc spring 102 can generate a preload force on the piezoelectric stack 104, preventing the piezoelectric stack 104 from being damaged by tensile force, and keeping the piezoelectric stack 104 in a compressed state at all times, which helps to improve the service life of the device.
[0039] In this embodiment, the side of the adapter closest to the piezoelectric stack 104 is spherical. This avoids bending moment on the piezoelectric stack 104, thereby helping to further improve the service life of the device.
[0040] like Figure 1 As shown, a circular hole is provided on the outer sleeve 2, and the diameter of the circular hole is larger than the diameter of the piezoelectric housing 103; the top of the piezoelectric housing 103 extends out of the outer sleeve 2 through the circular hole. By providing a circular hole in the outer sleeve 2, the piezoelectric actuator 1 can move up and down relative to the outer sleeve 2.
[0041] In this embodiment, the height of the piezoelectric housing 103 is greater than the maximum stroke of the magnetorheological damper 3. This arrangement can prevent collisions between moving parts and extend the life of the equipment, while also ensuring that the piezoelectric drive and damping adjustment work together throughout the entire stroke.
[0042] This embodiment also provides a vibration reduction and isolation method, which uses the above-described device. Figure 3 A schematic flowchart of the vibration reduction and isolation method of this embodiment is shown. Figure 3 As shown, the method includes the following steps S310 and S320.
[0043] In step S310, the first vibration signal collected by the first vibration sensor is acquired.
[0044] At step S320, at least based on the first vibration signal, the voltage of the piezoelectric stack and the current of the magneto-rheological damper are controlled to offset the vibration energy.
[0045] The method has simple operation, can realize adaptive vibration reduction and isolation according to the first vibration signal, has fast response speed, and can have good vibration reduction and isolation effect under vibrations of different frequency bands.
[0046] In the embodiment, at step S320, at least based on the first vibration signal, the voltage of the piezoelectric stack and the current of the magneto-rheological damper are controlled, including: determining a dominant frequency of the external excitation based on the first vibration signal; when the dominant frequency is in a low frequency band, adjusting the voltage of the piezoelectric stack based at least on the first vibration signal; when the dominant frequency is in a medium frequency band, adjusting the current of the magneto-rheological damper based at least on the first vibration signal; and when the dominant frequency is in a high frequency band, closing the piezoelectric stack and the magneto-rheological damper.
[0047] The vibration reduction principle of the embodiment is as follows: in a low frequency band, the natural frequency of the system is changed by changing the stiffness of the variable stiffness spring to avoid the resonance point in real time, and the piezoelectric driver actively outputs a control force, which has the advantages of fast response speed, high thrust density, and high resolution, can effectively suppress low-frequency vibration, and makes up for the insufficient performance of traditional semi-active or passive vibration isolation in the low frequency band. In a medium frequency band, the adjustable damping characteristics of the magneto-rheological damper are used to adjust the damping force in real time by changing the excitation current, to realize semi-active control, which can significantly improve the vibration attenuation effect in the medium frequency band, and avoid the defects of large energy consumption and poor stability of the active system. In a high frequency band, only passive isolation is relied on, without additional energy consumption, the high-frequency vibration can be effectively attenuated, and the problems of efficiency reduction and service life shortening of the active actuator under high frequency are avoided. Through the above frequency band cooperative vibration reduction and isolation strategy, the optimal control mode can be adopted for vibrations in different frequency ranges, to realize efficient vibration isolation in the full frequency band and greatly improve the overall vibration isolation performance of the system.
[0048] In the embodiment, adjusting the voltage of the piezoelectric stack based at least on the first vibration signal includes: at least based on the first vibration signal, and using an active control algorithm to calculate to obtain the voltage of the piezoelectric stack; and / or, adjusting the current of the magneto-rheological damper based at least on the first vibration signal includes: at least based on the first vibration signal, and using a semi-active control algorithm to calculate to obtain the current of the magneto-rheological damper.
[0049] The active control algorithm can be FxLMS, LQR, etc. In some embodiments, the FxLMS algorithm is used to calculate the voltage of the piezoelectric stack. In this embodiment, a second vibration sensor is mounted on the vibration source, and both the first vibration sensor and the second vibration sensor can be acceleration sensors. The vibration signal collected by the second vibration sensor on the vibration source can be referred to as a second vibration signal. The FxLMS algorithm can calculate the voltage of the piezoelectric stack based on the first vibration signal and the second vibration signal. In this embodiment, the second vibration signal can be used as a reference signal to represent the component of the external disturbance to be input. The first vibration signal can be used as a vibration response to provide an error signal for the FxLMS, reflecting the vibration isolation effect, and serving as a basis for performance evaluation. In other embodiments, the LQR algorithm can be used. In this embodiment, the first vibration sensor can include an acceleration sensor and a displacement sensor, and the displacement, acceleration, and driving force of the isolated structure are used as control targets to obtain the performance function of the LQR controller.
[0050] The semi-active control algorithm can be, for example, a skyhook control algorithm or a fuzzy control algorithm. In some embodiments, both the first vibration sensor and the second vibration sensor can be acceleration sensors. In this embodiment, the absolute speed of the isolated structure and the relative speed between the isolated structure and the vibration source can be obtained by integrating the acceleration, and the current of the magnetorheological damper can be calculated based on the absolute speed and the relative speed using the skyhook control algorithm. In other embodiments, the fuzzy control algorithm is used to calculate the current of the magnetorheological damper. In this embodiment, the absolute displacement of the isolated structure (obtained by integrating the acceleration or detected by a displacement sensor), the acceleration of the vibration source, and the peak value of the response acceleration of the isolated structure under passive control can be used as inputs to obtain the current of the magnetorheological damper.
[0051] The above scheme uses mature algorithms such as active control algorithms and semi-active control algorithms for calculation, which can improve the accuracy and reliability of the calculation results, and thus can achieve precise vibration reduction response of the device.
[0052] In this embodiment, based on the first vibration signal, the dominant frequency of the external excitation is determined, including: performing fast Fourier transform processing on the first vibration signal to obtain the frequency distribution of the first vibration signal; and determining the dominant frequency based on the frequency distribution.
[0053] It can be understood that the vibration signal collected initially is a time domain signal itself. In the embodiment, the time domain signal is subjected to fast Fourier transform (FFT) processing to convert the time domain signal to the frequency domain, so as to obtain the frequency distribution of the vibration signal. Specifically, taking the first vibration signal as an acceleration signal as an example, the FFT processing process is as follows: the collected acceleration signal is subjected to direct current removal and pretreatment; the sampling frequency and the sampling point number are set, the signal is segmented and windowed to reduce the frequency spectrum leakage; the frequency domain amplitude spectrum is obtained through fast Fourier transform; and the actual frequency distribution and the acceleration amplitude at each frequency point are obtained by combining the sampling rate and the point number. After the FFT processing, the response intensity of the vibration isolation structure at each frequency can be obtained in real time, and the main excitation frequency band is identified accordingly. The obtained frequency distribution result will be used as the input of the subsequent control strategy to determine the input current size of the magneto-rheological damper and the driving voltage size of the piezoelectric driver, so as to realize the optimal adjustment of the vibration isolation performance.
[0054] In the embodiment, the interference vibration above 100 Hz is referred to as high-frequency vibration, the vibration of 10-100 Hz is referred to as medium-frequency vibration, and the vibration below 10 Hz is referred to as low-frequency vibration.
[0055] Those skilled in the art can easily understand the implementation structure, working principle and beneficial effects of the device used in the vibration isolation method by reading the above device. For brevity, it will not be repeated here.
[0056] Although the example embodiments have been described herein with reference to the accompanying drawings, it will be understood that the example embodiments described above are merely exemplary and are not intended to limit the scope of the present application. Those skilled in the art can make various changes and modifications without departing from the scope and spirit of the present application. All these changes and modifications are intended to be included within the scope of the present application as claimed in the appended claims.
[0057] Those skilled in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware or in combination of computer software and electronic hardware. Whether the functions are realized in hardware or software mode depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.
[0058] In several embodiments provided by the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative, for example, the division of units is only a logical function division, and actual implementation can have another division mode, for example, a plurality of units or components can be combined or integrated into another device, or some features can be ignored or not executed.
[0059] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the application can be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.
[0060] Similarly, it is to be understood that the mechanical details of the application that have been set forth in the description in connection with exemplary embodiments of the application are intended merely to be illustrative and that no limitation of the scope of the application is intended to be implied therefrom. Furthermore, it is to be understood that the phraseology and terminology employed herein are by way of description and should not be regarded as limiting. As should be recognized, various embodiments of the application can be comprised of one or more conventional processors and unique stored program instructions that control one or more processors to implement, in conjunction with certain non-processor circuits, some, most, or all of the functions of the method steps and / or processes described herein. The non-processor circuits can include, but are not limited to, a battery, simple logic for performing one or more of the functions described herein, a magnetic storage media, and interfaces for various input / output devices (such as but not limited to keyboards, monitors, storage devices, etc.). The limitations in which the processor might be for example are that it: has finite computational resources and memory; can only process hardware implemented instructions, and software implementations can only run on software, virtual machines, and / or welfare platforms; and has limited time in which to solve particular problems because that is all that is required of a typical hardware / software / circuit imbedded in a real time system. In addition, the description uses the term "processor" and "computer" in a generic sense to include one or more real or virtual processor(s), conventional or non-conventional circuits, and related non-processor circuitry.
[0061] Those skilled in the art will appreciate that all features described in this specification (including the summaries of the application and the abstract), and / or all elements of the device and / or method described, can be claimed in any combination. Unless otherwise expressly stated, each
[0062] In addition, those skilled in the art will appreciate that, unless otherwise indicated herein, the various embodiments of the present application described herein are not mutually exclusive, but can be combined in any manner. For example, in the claims, any of the claimed embodiments can be used in any combination.
[0063] Various component embodiments of the present application can be implemented in hardware, or as software modules running in one or more processors, or in combinations thereof. As will be appreciated by one skilled in the art, a microprocessor or digital signal processor (DSP) can be used in practice to implement some or all of the functionality of the control module according to embodiments of the present application. The present application can also be implemented as an apparatus program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such program implementing the present application can be stored on a computer readable medium, or can have one or more signals. Such signals can be downloaded from an Internet website, or provided on a carrier medium, or in any other form.
[0064] It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and that one skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word 'comprising' does not exclude the presence of elements or steps other than those listed in a claim. The word 'a' or 'an' preceding an element does not exclude the presence of a plurality of such elements. The application can be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a unitary claim, several of the devices, apparatuses or means can be presented in the form of a single product since these devices, apparatuses or means can be physically, but not necessarily logically, combined with one another. The use of the words first, second, third, etc. do not imply any order but rather are used for identification purposes only. These words are not meant to be construed as limiting.
[0065] The above description is only specific embodiments of the present application or specific explanations of the specific embodiments, and the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, and all of them should be covered within the protection scope of the present application. The protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A vibration isolation and / or mitigation device based on magneto-rheological dampers and piezoelectric stacks, characterized in that, Comprising: an outer sleeve, a magneto-rheological damper, a piezoelectric driver, an intermediate mass, a lower cover plate, a first vibration sensor and a control module; the lower cover plate is arranged at the bottom of the outer sleeve; the lower cover plate is used for connecting a vibration source; the first vibration sensor is used for collecting a first vibration signal of a vibration-isolated structure; the magneto-rheological damper, the piezoelectric driver and the intermediate mass are all located in a space composed of the outer sleeve and the lower cover plate; the piezoelectric driver comprises a piezoelectric shell, an output rod and a piezoelectric stack; the piezoelectric stack is arranged in an inner cavity of the piezoelectric shell, the output rod is connected with the piezoelectric stack at the bottom and penetrates through the piezoelectric shell at the top to be connected with the vibration-isolated structure; the piezoelectric shell is connected with the intermediate mass at the bottom, and the intermediate mass can slide up and down in the outer sleeve; the upper end of the magneto-rheological damper is hinged to the outer sleeve, and the lower end is hinged to the top of the intermediate mass; the control module is connected with the first vibration sensor, the piezoelectric stack and the magneto-rheological damper; the control module is used for acquiring the first vibration signal collected by the first vibration sensor, and at least based on the first vibration signal, controlling the voltage of the piezoelectric stack and the current of the magneto-rheological damper to offset the vibration energy.
2. The apparatus of claim 1, wherein, Further comprising a spring; the top of the spring is connected with the bottom of the intermediate mass, and the bottom is connected with the lower cover plate; Preferably, the spring is a variable stiffness spring.
3. The apparatus of claim 2, wherein, Both sides of the spring are provided with a retainer.
4. The apparatus of claim 2, wherein, The number of the magneto-rheological dampers is multiple, and the multiple magneto-rheological dampers are uniformly arranged relative to the piezoelectric driver; the number of the springs corresponds to the number of the magneto-rheological dampers, and the springs are arranged on the opposite side of the magneto-rheological dampers relative to the mass.
5. The apparatus of claim 1, wherein, The bottom of the output rod is provided with an adapter, and the output rod is connected with the piezoelectric stack via the adapter; a disc spring is arranged between the adapter and the top wall of the inner cavity of the piezoelectric shell, and the disc spring is sleeved on the output rod; Preferably, the side of the adapter close to the piezoelectric stack is spherical.
6. The device of any one of claims 1-5, wherein, A circular hole is arranged on the outer sleeve, and the diameter of the circular hole is greater than the diameter of the piezoelectric shell; the top of the piezoelectric shell penetrates through the outer sleeve via the circular hole.
7. A method of vibration isolation, characterized by The device of any one of claims 1-6 is adopted; the method comprises: acquiring the first vibration signal collected by the first vibration sensor; at least based on the first vibration signal, controlling the voltage of the piezoelectric stack and the current of the magneto-rheological damper to offset the vibration energy.
8. The method of claim 7, wherein, The at least based on the first vibration signal, controlling the voltage of the piezoelectric stack and the current of the magneto-rheological damper, comprises: determining the dominant frequency of the external excitation based on the first vibration signal; when the dominant frequency is in a low frequency band, at least based on the first vibration signal, adjusting the voltage of the piezoelectric stack; when the dominant frequency is in a medium frequency band, at least based on the first vibration signal, adjusting the current of the magneto-rheological damper; when the dominant frequency is in a high frequency band, turning off the piezoelectric stack and the magneto-rheological damper.
9. The method of claim 8, wherein The adjusting the voltage of the piezoelectric stack based on at least the first vibration signal comprises: calculating, based on at least the first vibration signal and using a passive control algorithm, the voltage of the piezoelectric stack; and / or, The adjusting the current of the magnetorheological damper based on at least the first vibration signal comprises: calculating, based on at least the first vibration signal and using a semi-active control algorithm, the current of the magnetorheological damper.
10. The method according to claim 8 or 9, characterized in that, The determining the dominant frequency of the external excitation based on the first vibration signal comprises: performing fast Fourier transform on the first vibration signal to obtain a frequency distribution of the first vibration signal; determining the dominant frequency according to the frequency distribution.